DROUGHT MONITORING SYSTEM IN DHMZ Ksenija Cindrić, D. Mihajlović, J. Juras L. Kalin, B. Matjačić ksenija.cindric@cirus.dhz.hr National Seminar on Drought Management 16 th April 2012, Zagreb /15 /15 1

National Seminar on Drought Management overview Introduction Drought monitoring methods 2.1. Daily scale 2.2. (Multi)Monthly scale 2.3 Drought forecast 3. Future improvements 16/04/2012 National Seminar on Drought Management /15 /15 /15 2

National Seminar on Drought Management 1. Introduction In Croatia drought causes highest economic losses (39%) among all hydromet events (DPPŠEN,2009) In last 2 decades it caused serious damage in agricultural sector (30% crop diminishing) Climate change (IPCC, 2007)– mean annual precipitation increases in northern Europe and decreases further south, more intense and longer droughts Positive trend in dry spells in CRO (spring) (Cindrić et al.,2010) 16/04/2012 National Seminar on Drought Management /15 /15

National Seminar on Drought Management => an increasing interest in developing methods for drought warning system in Croatia Comprehensive drought early warning system should provide (Lincoln declaration on drought indices, 2010): - drought monitor (drought indices) - provide an early warning of drought onset and it’s intensity in timely manner - have drought prediction compoment (to protect crops, fire risk, water supply... ) 06/03/2012 National Seminar on Drought Management /15 /15 4

National Seminar on Drought Management DHMZ drought monitoring system: Monthly scales (maps and graphs): - Standardized Precipitation Index(SPI) - precipitation ratio against normal - difference from normal - associated percentiles - return periods - 1, 3, 6, 12, 24 and 48 months scales Daily scale - ‘Peacock tail’ 16/04/2012 National Seminar on Drought Management /15 /15 5

National Seminar on Drought Management DHMZ web site (http://www.meteo.hr/) - daily and monthly updated DHMZ monthly bulletin - few months delay - description of monthly situation - add. – dry/wet spells analysis - return periods due to daily SPI 16/04/2012 National Seminar on Drought Management /15 /15 6

National Seminar on Drought Management Climate Prediction Center of NOAA http://www.cpc.ncep.noaa.gov/products/global_monitoring/pre cipitation/ ALPINE & SOUTHEAST EUROPE 16/04/2012 National Seminar on Drought Management /15 /15 /15 7

National Seminar on Drought Management Time series of accumulated actual daily precipitation time series and accumulated normal precipitation are updated daily for stations in given regions. 16/04/2012 National Seminar on Drought Management /15

National Seminar on Drought Management 2. Drought monitoring methods 16/04/2012 National Seminar on Drought Management /15 /15

2.1. Daily scale – ‘peacock tail’ - year month station -square-root normal distribution Juras (1994) Juras&Cindric (2010) daily updated 16/04/2012 National Seminar on Drought Management /15

National Seminar on Drought Management 2.2. Monthly scales 16/04/2012 National Seminar on Drought Management /15

Standardized Precipitation Index (SPI) universal measure of meteorological drought recommended by WMO developed by McKee et al (1993) suitable tool for assesing drought intensity and duration uses only the precipitation data at given location can be calculated for different time scales - separates different types of drought (meteorological, hydrological, agricultural) 16/04/2012 National Seminar on Drought Management /15

Gamma CDF is transformed to a standardized normal distribution N(0,1) pdf: cdf: a – shape parameter b – scale parameter x – precipitation amount - calibration period: 1961-2000 q – probability of zero preciptiation SPI > 0 : precipitation > median SPI < 0 : precipitation < median > 2.0 extremely wet 1.5 to 1.9 very wet 1.0 to 1.49 moderately wet -0.99 to 0.99 normal -1.0 to –1.49 moderately dry -1.5 to –1.99 very dry < -2.0 extremely dry 16/04/2012 National Seminar on Drought Management /15

National Seminar on Drought Management SPI spatial distribution 1,3,6,12,24,48 m calibration period: 1961-2000 monthly updated September 2010 16/04/2012 National Seminar on Drought Management 14 /15 /15 14

National Seminar on Drought Management Drought example November 2011 March 2012 16/04/2012 National Seminar on Drought Management 15 /15 /15 15

National Seminar on Drought Management 2.3. Drought forecast ECMWF precipitation forecast: - medium range ( 9 days) - monthly (28 days) - seasonal (1 month) daily and monthly precipitation records for 5 met. stations representing different climate regions in Croatia 2007 -2011 16/04/2012 National Seminar on Drought Management /15 16

National Seminar on Drought Management observed ECMWF forecast 21 days 9 days SPI 30d 28 days SPI 28d 1 month SPI 1 2 months 1 month SPI 3 16/04/2012 National Seminar on Drought Management /15

National Seminar on Drought Management SPI30d (21 observed + 9 forecasted) skillful slight overestimating of SPI (too wet) often still not catching extreme events 16/04/2012 National Seminar on Drought Management /15

National Seminar on Drought Management Monthly and seasonal forecasts (SPI28, SPI1 and SPI3) significantly less skill signal too weak (no extreme forecasts) 16/04/2012 National Seminar on Drought Management /15

National Seminar on Drought Management 3. Future improvements Comprehensive operational monitoring system in DHMZ Weak feedback from endusers Improve monitoring system Establish operational SPI forecast (SPI30) combining observation and forecast Develop operational drought warning system 16/04/2012 National Seminar on Drought Management 20 /15 /15 20

Thank you for your attention! 16/04/2012 National Seminar on Drought Management 21 /15 /15 21